The US economy grew at an annualised rate of 1.7% in the second quarter of the year, slightly faster than previously thought.
Stronger exports helped push the figure higher than the initial estimate of 1.5%, the Commerce Department said, but remains below the 2% needed to lower the unemployment rate.
The revision also reflects better-than-expected consumer spending and improved state and local government spending.
Annalisa Piazza, market economist at investment company Newedge, described the revision as a "touch more encouraging".
"In a nutshell, the US economy still struggles to gain momentum and it remains well below potential," she said.
But despite being higher than previously thought, the GDP figures represent sluggish growth when compared with the 2% of the first quarter of 2012.
The growth rate is unlikely to be strong enough to banish speculation that the US central bank could further loosen monetary policy at its meeting in September.
The chairman of the Federal Reserve, Ben Bernanke, is expected to fuel expectation of a third round of quantitative easing at a conference of central bankers in Wyoming on Friday.